Photonic devices have been integrated with a number of semiconductor technologies. Such integrated devices may have improved performance and/or additional functionality. In such integrated photonic circuits, it is desirable to support the vertical transfer of optical data between multiple layers of the device. Stated differently, optical data is desired to be transferred from a photonic device on one layer of the integrated device to another photonic device on another layer of the integrated device.
Various technologies have been developed to facilitate optical transmission between layers of the integrated device. Vertical transmission from one photonic device to another may involve waveguide to waveguide transmission between vertical waveguides. For transmission between vertical waveguides, the spacing may be desired to be twenty nanometers to not more than three hundred nanometers. Thus, such vertical transmission of optical data is limited to very small distances. Very large optical vias can vertically transmit optical data. However, these vias are multimode, which is undesirable. Large waveguides on silicon may be used to transfer optical data. Such waveguides are generally multimode and couple light into the silicon substrate, both of which are undesirable. Some such approaches also require turning mirrors, which provide a forty-five degree reflective surface to reflect light from a waveguide to the large optical via. Such mirrors are generally challenging to fabricate at small sizes.
Consequently, an improved mechanism transmission of optical information is desired.